Chapter 3, The Nature of Matter Summary and Analysis

Supposing matter exists, what is its nature? Physical science gives an incomplete but respectable answer. It seems to assume that everything material can be reduced to motions and wave-motions specifically. Although, wave-motions and things like light are not identical, the latter can be explained in terms of the former. When we save that light is a wave, we mean that waves cause the physical sensation of life. This is true not only of colors and sounds but of space as well.

Physical objects and sense-data are not the same thing; instead, the former cause the latter. The physical objects in science are those that cause such sensations. Physical science and common sense assume that there is one public physical space where all physical objects are located. However, what can we know about it...